Apparatus for making screen cloth



May 19, 1942. R. D. HELLER APPARATUSAFOR MAKING SCREEN CLOTH Filed Nov. 25, 1941 Patented May 19, 1942 UNITED STATES PATENT OFFICE APPARATUS FOR MAKING SCREEN CLOTH 'Richard D. Heller, Columbus, 'Ohio Application November 25, 1941, Serial No. IV420,389

(CLIM- 3) 21 Claims.

This invention relates to a new and improved apparatus for making screen cloth, vparticularly of the type comprising a pluralityof parallel strands of wire as distinguished from wire woven type of screen cloth.l

One of the objects of the present invention is the provision of improved apparatus for connecting cross-strips to the parallel strands of wire of a non-woven wire screen cloth.

A further object of the invention .is the provision of improved and eicient lifting and adjusting mechanism for soldering apparatus applied to Aconnecting bars or transverse strips Vto secure the same to parallel wires of the screen cloth panel while such wires are held taut by means of tensioning mechanism.

Another object of the invention isthe provision of equalizing mechanism for Vthe supporting means of soldering apparatus applied to connecting bars or transverse strips to facilitate the securing of the latter to the parallel wires of a screen cloth panel.

A further object ofthe invention is the provision of heat radiating means for soldering apparatus supporting mechanism to reduce to a minimum the expansion of the latter during the soldering of connecting bars or 'transverse strips to the parallel wires of a screen cloth'panel.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawing,

Fig. 1 is an elevational View, partly insection, of the mechanism for supporting the end .bars cf a screen cloth while applying tension' thereto;

Fig. 2 is an elevational view of one of. the parallel motion jacks of Fig. l;

Fig. 3 is a plan View .of the carrier for the soldering apparatus, with the .serrated bars of Fig. 2 omitted;

Fig. 4 is an enlarged sectional view taken on the line 4-4 of Fig. 2, looking in the .direction of the arrows;

Fig. 5 is a sectional view similar Yto that 'shown in Fig. 4, but disclosing the form :shown 'in my co-pending application, Ser.r No. 346,342, Viiled July 19, 1940, for a Method of making'screen cloth; and

Fig. 6 shows the construction of one of the intermediate strips produced either by the form of soldering apparatus shown in Fig. 4 or the form of soldering apparatus shown in Fig. 5.

The apparatus shown yin the accompanying drawing is particularly adapted to operate upon an elongated panel i 51 vcomposed of parallel spaced-apartpiano wires or the like, secured at their ends as `vby Asoldering to .connecting end bars 52 and 56. My improved apparatus shown in the accompanying drawing has been produced to'further treat .such panel by securing thereto connecting strips 19 in parallel relation to the end bars 52 and 56 so that the completed screen cloth may be efficiently used in vibrating apparatus, with the end bars 52 and 56 and the connecting strips 19 extending longitudinally of the direction of the vibration. The apparatus shown in Fig. 1 is also adapted to subject the panel 51 to further treatment to make a plurality of sections of 'screen cloth each having end bars, such as 52, 14 and 56, 13, and leach having one or more intermediate connecting strips 19.' These operations which can be performed on ,the panel 51 will now be described.

Mechanism for treating the panel of lscreen clothr51 is vin the form of a tableV 53 vcomprising fa main Vframe 59 which I have found can be conveniently made by merly taking a desired length of very heavy vI-beam to the end of which Vis `attached a bracket having at .its top a holding bracket 6I for removably receiving one ofthe end bars, such as the end bar 52. The bracket 6I may take the form of the bracket associated with the deck of the screen which attaches the screen cloth thereto, as disclosed and claimed in my copending application, Serial No. 234,014, rfiled October 8, 1938, for lan improvement in Screens.

To provide for supporting and stretching the panel of screen cloth 51, I have shownin Fig. l means for attaching the other end bar 56 `to an adjustable. bracket 62 which is slidable along the top flanges of the main frame 59 soas to `be positioned at the proper' distance Y from the bracket 60 to receive the length of panel of the screen cloth 51, it being, of course, understood that the length of these panels will vary from time to time.

The bracket 62 comprises a box-like construction 63 which may be formed by welding together a pair 'of angular members from which extends downwardly a pair of spaced arms 64, 64 which extend below the top flanges of the main frame 59. Extending vinwardly from each of the arms 64, 64 is a locking block 65. Extending upwardly from the box-like construction 63 is an arm B5 which has an appreciable width and is provided with spaced re-inforcing plates 61. Extending yacross the face of the arm 66 is a shelf 68 upon which is slidably mounteda plate 69 to which is attached a plurality vof bolts 10, the latter extending through the arm 66 to receive the nuts 1|. The plate 69 also carries an attaching bracket 12 similar to the attaching bracket 6|, for removable attachment to the end bar 56 of the panel of screen cloth 51.

To adjust the bracket 62 to the desired position to receive the end bar 56, it is moved to the dotted line position shown in Fig. 1 of the drawing where one side of the box 63 has a large bearing area of contact with the top flanges of main frame 59, under which conditions the locking block 65 is spaced from the lower surfaces of the top flanges of main frame 59, whereupon the bracket 62 may slide freely along said mainY frame 59. When the bracket 62 has reached the position desired, it is rotated clockwise from the dotted line position illustrated in Fig. 1 of the drawing, to `the full line position, in which position there is a relatively sharp edge of the boxlike construction 63 in contact with the top of the main frame 59, and the two locking blocks 65 are in contact with the lower surfaces of said flanges in a position to the left of that position where said edge of the box 63 contacts with the top of the main frame 59. Under these conditions itis, of course, evident that any force which tends to rotate the bracket 62 in a clockwise direction will effect a clamping action between said sharp edge of box 63 and the top surface of main frame 59 and between the clamping block 65 and the bottoms of said flanges, thus securely clamping the bracket 62 in place. Such action is, of course, afforded by the tensioning of the panel of screen cloth 51 which is effected by virtue of the connection of the end bar 56 to the attaching bracket 12, the ultimate tension being applied by adjusting the nuts 1|, the end bar 56 being attached to bracket 12. The nuts 1| are adjusted to tension the panel of screen cloth 51 evenly over the entire area.

With the panel of screen cloth 51 thus tensioned on the table 58, the next operations are those of attaching the desired number of end bars and intermediate strips. In the illustration given, the panel 51 was to be made into two sections of screen cloth, and consequently it is necessary to attach two additional end bars. Such end bars are illustrated at 13 and 14 in Fig. 1 of the drawing, and their manner of attachment will now be described.

I provide one or more parallel motion jacks 15, each of which has a bottom plate 16 and a top plate 11. Each top plate can be adjusted in height with respectto the bottom plate 16 by screw-operated parallel link mechanism 18 while maintaining the top plate 11 parallel to the bottom plate 16 at all times. The bottom plates 16 of the jack merely reston the top surfaces of main frame 59 so that either jack 15 may be placed in any position along the I-beam. A plurality of such jacks are preferably employed so that a plurality of operators may perform the advance functions which are to be performed on the screen cloth 51 simultaneously.

To attach the end bars 13 and 14 and crossstrip 19, as shown in Fig. l, generally similar operations are performed. The operation of attaching the cross-strip 19 will now be described.

The jack 15 is placed at the desired position below that where the cross-strip 19 is to be permanently secured to the parallel wires of the screen cloth, and said jack is adjusted so that the plate 11 is at approximately the proper height. The plate 11 is provided with spacedapart transverse webs 80, 80, the upper edges of which extend transversely of the plate 11 in parallelism to each other and all in the same horizontal plane. In fact, the upper edges of the webs 88, 89 are narrow and transversely elongated to receive the bars 85, each of which is in the shape of a segment of a cylinder with its rounded surface on the under side and its upper flat surface permanently secured as by welding to the bottom central portion of the channel |45.

The upper edges 86, 86 of the vertical spacedapart walls of the channel |45 are provided with adjacent pairs of clips 81, 88 between which are mounted the serrated guide strips one of which is shown at |41 in elevation in Fig. 2. These guide strips |41 rest loosely on the edges 85, 86 of the channel |45 between the clips 81, 88, and each of such guide strips |41 may be formed by cutting longitudinal strips from a threaded pipe, thereby providing the serrations |41' for receiving the wires of the panel 51.

Secured to the inner walls of the upright ilanges of the channel |45 are inwardly projecting vertical spacers 90, 9|. Between these spacers is mounted an elongated heating element |5| which is preferably coextensive with the length of the channel |45. On the bottom of the heating element |5| is an elongated metal plate |56 of the same length and width as the heating element. Resting on top of the heating element is a metal tray |53 of the same length as the heating element |5| and having a bottom of the same width as that of the heating element |5|. The metal tray |53 is lined at |53 with solder-resistant material, such as asbestos. Within the tray |53 above the interlining |53 is a metal hot plate 8| having an elongated trough 82 adapted to receive a plurality ofwires 83 closelyadjacent to each other and in parallelism.

After the channel |45 and the parts associated therewith are in their proper places, the jack 15 is adjusted to force an intimate contact between the guide strips |41 and the wires 3| of the screen panel 51, whereupon the transverse webs 8l), 80 will, by contact with the rounded bars 85, force the serrations |41' upwardly against the wires 3|. By reason of the lower rounded surfaces of the bars 85, the channel |45 will be free to rock or tilt transversely of itself, thus equalizing the upward pressure of the serrations |41' againstv wires 3| of the screen receiving the vertical rods 93, the upper ends of which areprovided with flat circular heads 94 in position to engage at spaced-apart positions the lower surfaces of the metal base plate |58, as shown in Fig. 4. Springs 95 rest on the horizontal legs of.' the L-shaped brackets 92, and a washer 96 rests on the top of each spring. By means of cotter pins 91 extending diametrically through holes in the Vertical rods 93, downward movement by pressure on the top head 94 of the pin 93l will be limited by the spring 95. Upward movement of the pin 93 will be limited by engagement of the cotter pin 91 with the botis reached, the lower end of the pin 93 still re- 'mains in the hole .in vthe horizontal 'leg of the .-L- shaped bracket 92 and therefore so long as the -cotter pin remains in its position relative `to the -pin 93, -neither the washer 98 nor the lspring 95 Will be released from their `relative positions.

The adjustments of the relative positions of the spring95, washer 96 and cotter Vpin 91 rela- -tive to the .pin 493 and the horizontal leg of the `bracket 92 are preferably such that when the soldering apparatus rests on the distributed circular heads A94, the hot plate 8| will have its upper surface above .a plane extending through the serrations |41. Consequently, when the guiding strips |41 are brought into engagement `with Vthe under sides ofthe wires 3| by operation .of the lifting jack 15, the hot plate 8| together with the wires 83 in the trough 82 will be pressed against the under sides of the wires 3|, and this 4action will result in compression of the springs 95. These springs may be relatively strong because the wires 3| of the screen panel 51 may have considerable tension exerted thereon before the soldering apparatus is brought into operation. That is to say, since the wires 3| have considerable tension thereon during soldering operations, the lifting jack may be operated with `sufficient force to yfirmly press the channel bar |45 against the under sides of the wires 3|. Therefore, since the springs 95 are strong, they will have sufficient force, when compressed, to Very firmly hold the hot plate 8| and the strip wires 83 in rm contact with the wires 3|. Inasmuch as the springs 95 are distributed along the channel |45, as shown in Fig. 2, the strip wires 83 together with the hot plate 8| will be held firmly against the wires 3| throughout the lengths of the hot plate 8|.

The heating element |5| is preferably of the electrical type and when the electric current is turned on, sufficient heat will be transmitted through metal tray |53, the asbestos lining |53 and the hot plate 8| to the trough 82 to raisethe temperature of the wires 83 so that when solder is applied, they will be soldered together and also to the under sides of the wires 3|. A metal plate cross-strip 84 may also be soldered at the same time to the upper sides of the wires 3|, as shownv in Fig. 4. It should be understood, however, that the panel 51 is upside down, as shown in Fig. 1, and therefore Vthe wires 3| in Fig. 4 are Y also upside down, but in Fig. 6 the cross-strip is right-side up because when mountedon the deck of the vibrating apparatus, the wires 83 are on top and the metal plate strip 84 underneath, since' the cross-strip of parallel wires 83 'is stronger r than the metal cross-strip 84.l

Inasmuch as it is desirable to maintain the wires 3| of the screen equally spaced-apart and at predetermined distances from each other `during the soldering operation, I have not only spaced the inner Walls of the vertical flanges of the channel |45 from the edges of the elongated soldering mechanism by means of the spacers 90, 9|, but I have also provided a multiplicity of bottom openings 98, 99 under the lateral edges of the heating element |5|. The lateral anges of the tray |53 extend toward the guide strips |41 but remain spaced therefrom. This arrangement provides for upward currents of air toward the inner edges of the guide strips |41, keeping the latter sufficiently cool to prevent undue expansion thereof, and therefore permitting the predetermined spacings between the Wires 3| to be retained sufficiently during soldering operations vto assure the desired yspacing vbetween the wires 3| after the soldering .of the crossstrips to the Wires `3| has been completed.

The form shown in Fig. 5 is disclosed Yin my co-pending application, Serial No. 346,342, filed July 19, 1940, `for `an improvement in Method of 'and apparatus for .making screen cloth. In this form the plate 11 .and the web L80' correspond to the plate 11 yand web 80 in Fig. 2, in that a parallel ymotion jack 15 is `used for lifting the elongated channel upwardly `so that the serrated guide strips |41" will be forced against the lower sidesofthe wires 3 I. The bottom plate |50, the heating element 15|, the tray |53, ,the asbestos lining |53', and the hot plate 8| in Fig. 5 are similar to the corresponding parts thus designated in Fig. 4. In Fig. 5, however, -a series of set screws |55 ,is threaded through nuts |56 which are welded to the bottom of the channel |45. The `upper vends of these set screws |55 engage the bottom plates to force upwardly the heating element |5| and the parts mounted thereon to hold the wires 83 in proper position during `soldering operations.

With the parts adjusted as illustrated in Fig. 4 or with the parts adjusted as illustrated in Fig. 5, the vwires 83 may be forced into intimate contact with the wires 3| and the strip of solder which is laid on top of the wires 3| above the wires 83, is melted after a reasonable heating period by the heat from the electric heating element |5|. While the solder is in the molten condition a strip 84 of tin plate (sheet iron coated with tin) is laid on top of the wires 3 whereupon the electric current to the heater |-5| is cut off and the solder allowed to solidify with the tin plate strip S4 soldered to one'side of the wires 3| and the transverse wires 83 soldered tothe other side of with a plurality of parallel strands of wire with.V

end bars attached thereto yand a crossstrip formed of a plurality of strands of wire soldered to the parallel strands intermediate the end bars,

`is described and claimed in my -co-pending application, Serial No. 394,846, filed May 23, 1941, for an improvement in Screenv cloth and method of making same. To attach an end bar, such as an end bar 13 or an end bar 14, the operation is exactly the same as that required to attach a cross-strip 19 except for the fact of course that instead of the bar v8| I provide the end bar to be attached.

After the desired number of cross-strips 19 and end bars, such as end Ibars 13 and 14, have been attached, the panel of screen cloth 51 has its tension slackened by retracting the nuts 1| whereupon the panel 51 is cut between each pair of end bars which, in the illustration, will be between the end `bars 13 and 14. Thereafter, if the extended lengths of wire beyond the end bars are excessive, vthey may be clipped 01T, bent over said end bars and covered by strips of tin plate which extend beyond each edge of the associated end bar 13 or 14 and also bent over Yas shown in my Patent No. 2,220,106, granted November 5, 1940, for an improvement in Screen cloth and method of making same. In other words, the bent over ends of the wiresmay have soldered thereto strips of tin plate likewise bent over to cover the end portions of thewires 3l including the bent over ends. i

As previously indicated, it is possible to make more than two sections or panels of screen cloth on the table 58, and a number of such sections or panels can readily be predetermined by the available length of the table and the length of each section or panel desired. The number of persons that may be employed on the panel of screen cloth will vary with many conditions, but it is evident that more than one person may be employed at the same time in attaching end `bars or cross-strips.

It should also be noted that the number of tables 58 may be increased or decreased in accordance with the rate of supply of the panels 51. Under some conditions one table may be found to be ample, ybut if the panels 51 tend to pile up, a larger number of tables 58 may be provided, each supplied with the equipment shown in Fig. 1, to enable operations to be carried out on the panels 51 as fast as produced. This arrangement increases the flexibility of the operations and makes possible the maximum utilization of the equipment at all times which would not be possible if all the work of division into a plurality of panels and the addition of inter-v mediate connecting strips were to be performed on the apparatus by means of which the panel 51 is produced.

In the form shown in Fig. 5, the channel |45 may be lifted -oii the webs 80 only after the set screws |55 are removed from the nuts 155 whereas in the form shown in Fig. 4 the channel 145 together with the parts mounted thereon may be removed from the webs 80 whenever desired, since the middle bracket 92 extends through an opening in the plate 11 and the end brackets 92 are spaced beyond the ends of the plate 11, as shown in Fig. 2.

Furthermore, while the channel |45' may be provided on its bottom with rounded strips such as those designated 85 in Fig. 2, the channel |45 of Fig. 4 is preferred because of the heat radiating features embodied therein for association with the guide strips |41' to prevent the soldering mechanism from unduly heating and expanding such guide strips.

` This application is a continuation in part of my co'pending application, Serial No. 346,342, filed July 19, 1940, for an improvement in method of'making screen cloth.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and I therefore Wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

1. In mechanism for securing a connecting strip to a wire screen, the combination with a channel, of a heating element carried thereby, a tray mounted on said heating element, a layer of asbestos at the bottom of said tray, a hot plate in said tray on top of said layer of asbestos, a parallel wire cross-strip on said hot plate, and lifting mechanism extending through the bottom of said channel into engagement of said heating element to lift the latter and press the cross-strip on said hot plate against the Wires of the screen during the soldering operation.

2. Mechanism for attaching an intermediate connecting strip to a screen cloth comprising spaced parallel wires comprising the combination with supporting mechanism for the end bars connected to the spaced parallel Wires of the screen cloth, of a support for an intermediate strip comprising a plurality of closely adjacent transverse wires, means for placing the spaced parallel Wires of the screen cloth under tension, and means acting on said support to press said transverse lwires against the said spaced parallel wires preparatory to securing said transverse wires to each other and to said spaced parallel wires.

3. In mechanism for soldering connecting strips to a wire screen, thecombination with a support, of a channel bar mounted on said support to extend transversely of the screen intermediate the ends thereof, a heating element in the channel portion of the said channel bar, an additional channel above the said heating element, a hot plate in said last-named channel, a plurality of transverse wires on said hot plate and in contact with the Wires of the screen, and means for effecting lifting of the heating element to force said transverse Wires against the wires of the screen to facilitate soldering each transverse wire to the next adjacent transverse wire and all of said transverse wires to the Wires of the screen.

4. In mechanism for attaching connecting means to screen cloth wires, the combination with a support, of a channel bar mounted thereon, a heater located `in channel portion of the channel bar, a metal tray` mounted onV said heater, an asbestos lining for said tray, a hot plate in said tray, a plurality of transverse wires in a groove in lsaid hot plate, and a'rectangular strip of tin plate on top of the wires of the screen cloth and covering said'transverse wires, said heating element being adapted to heat said hot plate to effect soldering of said transverse wires to each other and to said rectangular strip as well as to the wires of the screen.

5. In mechanism for soldering cross-strips to a wire screen intermediate the ends of the latter, the combinatio-n with a support, of a channel bar mounted on said support toy extend transversely of the screen intermediate the ends thereof, a heating element in the channel portion of the channel bar, a metal channel above said heating element, a lining of solder resisting material in said tray, a hot plate in said tray, a plurality of transverse wires, each in contact with the next adjacent wire, means extending through said channel bar in position to act on the heating element to lift the latter to force the hot plate toward the wires of the screen and hold the said transverse Wires against the Wires of the screen, and a metal strip on top of the wires of the screen in position to cover said transverse Wires, said heating element being adapted to heat said hot plate to enable soldering of said transverse wires to each other and to said screen wires as well as to said metal strip.

6. In mechanism for soldering connecting strips to wire screens, the combination with a wire support, of a channel bar mounted on said support to extend transversely of the Wires of the screen, a heating element in the channel of the channel bar, a hot plate on said heating element and provided with a top groove, transverse wires in said groove below the wires of the screen, and means for lifting the heating element to effect pressing of said transverse wires against the wires of the screen during the soldering of said transverse Wires to each other and to the Wires of the screen.

7. In mechanism for securing connecting strips to a wire screen, the combination with mechanism for supporting the screen, of a carrier for supporting a plurality of closely adjacent wires on the underside of the screen, means acting on said carrier to press the said transverse wires against the underside of the screen, and means supported by said carrier to heat solder to secure said transverse Wires to the screen.

8. Mechanism for attaching .to a screen cloth an intermediate connecting strip composed of a plurality of adjacent parallel wires, comprising the combination with supporting mechanism for the end bars of the screen cloth, of means affording a trough for supporting such plurality of adjacent wires in parallelism to each other, means for placing the wires of the screen cloth under tension, and means acting on said trough means to press said adjacent wires against the wires of the screen cloth preparatory to securing said strip wires to the parallel screen Wires.

9. In mechanism for attaching an intermediate strip of adjacent wires to the wires of a screen cloth, the combination with supporting mechanism, of means for holding the Wires of the screen cloth on the supporting mechanism, means aiording a trough in which to support the adjacent wires for the intermediate strip, and mechanism for actuating said support to press said adjacent Wires against the wires of the screen cloth preparatory to securing said adjacent Wires to each other and to the wires of the screen cloth.

10. In mechanism for soldering a cross-strip of adjacent parallel Wires to a wire screen intermediate the ends of the latter, the combination with a support, of a parallel motion jack for adjusting the elevation of said support while keeping it level, a channel bar mounted on said jack to extend transversely of said screen, intermediate the ends thereof, a heating element in the channel portion of said channel bar, a channel of solder resisting material above said heating element, a hot plate in said last-named channel, said hot plate being provided with a trough for receiving a plurality of parallel adjacent wires for a transverse cross-strip, and means extending from said support through said channel bar to said heating element to lift the latter to force the parallel wires in said trough against the Wires of the screen cloth to facilitate soldering of said adjacent parallel wires to the wires of the screen cloth intermediate the ends of the latter.

11. In apparatus for securing a connecting strip to a wire screen intermediate the ends of the latter, the combination with a support, of a parallel motion jack for adjusting the elevation of said support while keeping it level, and means resiliently carried by said support for securing the connecting strip to the wire screen intermediate the ends of the latter.

12. In mechanism for securing a connecting strip to a Wire screen, the combination with mechanism for supporting the screen, of a carrier for the connecting strip adapted to be supported on the underside of the screen, and means comprising a plurality of spaced-apart resilient devices adapted to act on said carrier to press the strip against the underside of the wires of the screen preparatory to securing such strip to said screen wires intermediate the ends of the screen.

13. In mechanismfor securing a connecting strip to a wire screen, the combination with mechanism for supporting the screen, of a carrier for the connecting strip, and'means for yieldingly moving said carrier against the underside of the screen intermediate the ends of the latter, said moving means comprising a plurality of spacedapart springs for pressing the carrier and the connecting strip against the undersides of the Wires preparatory to securing the strip thereto.

14. In mechanism for securing a connecting strip to a wire screen intermediate the ends thereof, the combination with mechanism for supporting the screen, of an elongated carrier unit for the connecting strip, an elongated support, a plurality of spaced-apart springs for resiliently supporting said carrier on said support, and mechanism comprising a parallel motion jack for moving said support toward the screen to transmit pressure through said springs to said carrier to in turn press said connecting strip against the Wires of the screen preparatory to securing said connecting strip to said Wires.

15. In apparatus for soldering a, connecting strip to a wire screen, the combination with soldering mechanism, of an elongated channel for receiving said soldering mechanism, means for supporting said channel for movement into engagement with the wires of the screen, and a plurality of spaced-apart resilient devices between said channel and said soldering mechanism to yieldingly press the latter against the wires of said screen.

16. In apparatus for soldering a connecting strip to a wire screen, the combination with soldering mechanism, of a channel for receiving said soldering mechanism, serrated guide strips mounted loosely on the upper edges of said flanges of said channel, spaced clips extending upwardly from said iianges in position to engage the sides of said serrated strips to position the latter on said flanges, and means for moving said channel toward said screen to press said serrated strips against the wires thereof and for pressing said soldering mechanism against the Wires of the screen.

17. In apparatus for attaching a connecting strip to a wire screen, the combination with a support, of a channel mounted on said support to have a transverse rocking movement relatively thereto, means for pressing said channel against said screen while said channel is free to rock to a limited extent to eiect equalization of pressure of the flanges of said channel on the wires of the screen, and mechanism carried by said channel for adhesively attaching said connecting strip to the screen wires.

18. In apparatus for attaching a connecting strip to a wire screen, the combination with supporting plate, of a plurality of transverse spacedapart Webs on said plate with their upper edges in the same plane and each rectilinear, a channel, elongated strips on the bottom of said channel, each of said elongated strips having the shape of a segment of a cylinder and each resting on a plurality of said webs, soldering mechanism in said channel, and means for pressing said soldering mechanism against the Wires of the screen.

19. In apparatus for soldering a connecting strip to a wire screen, the combination with a channel having a multiplicity of spaced openings in the bottom thereof, of soldering mechanism in said channel, spacers to hold the edges of the soldering mechanism spaced from the inner vertical Walls of the flanges of the channel to permit free circulation of air through said openings past the edges of said soldering mechanism to the upper edges 'of the flanges of said channel to reduce the temperature of such edges, and means for eiecting contact between said upper edges and the Wires ofthe screen and contact between the soldering mechanism and such Wires.

20. Apparatus for soldering connecting strips to the Wires of a screen comprising the combination with an elongated channel, of L-shaped brackets secured to the bottom of said channel, a spring-pressed support on each bracket, and

soldering mechanism in said channel and resting on said spring-pressed supports.

21. Apparatus for soldering connecting strips to Wires of a screen comprising the combination of an elongated support, of a plurality of springpressed supports distributed along the bottom of said support, soldering mechanism adapted to rest on said spring-pressed supports, and means for positioning said rst-named support to bring said soldering mechanism into engagement with the Wires of said screen and cause said springvpressed supports to yieldingly hold said soldering mechanism against such wires.

RICHARD D. HELLER. 

